Distributed locking protocol with asynchronous token prefetch and relinquish

Abstract

Asynchronous messages are used to prefetch and / or relinquish tokens used in providing locking of shared resources. A message is sent to prefetch one or more tokens, and prior to receiving a reply for the message, another message (e.g., an acquire) is sent for at least one of those tokens. Similarly, a message is sent indicating a voluntary relinquish of one or more tokens and without having acknowledgment that the relinquish request was processed, a further message (e.g., an acquire) is sent for at least one of the tokens. Multiple tokens may be acquired and / or relinquished in a single message to the token server. This reduces message delays and overall message traffic.

Description

CROSS-REFERENCE TO RELATED PATENTS / APPLICATIONS

[0001] This application is a continuation of U.S. patent application Ser. No. 09 / 907,119, filed Jul. 17, 2001 and published Jan. 23, 2003 as U.S. Patent Publication No. US 2003 / 0018785 A1, entitled “Distributed Locking Protocol with Asynchronous Token Prefetch and Relinquish”, by Eshel et al., which is hereby incorporated herein by reference in its entirety. This application also contains subject matter which is related to the subject matter of the following patents, each of which is assigned to the same assignee as this application. Each of the below listed patents is hereby incorporated herein by reference in its entirety:

[0002] “Distributed Lock Manager Using a Passive, State-full Control-Server”, by Devarakonda et al., U.S. Pat. No. 5,454,108, issued Sep. 26, 1995;

[0003] “Parallel File System With Extended File Attributes”, by Schmuck et al., U.S. Pat. No. 5,940,841, issued Aug. 17, 1999;

[0004] “Parallel File System and Method for ...

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